Tubular locks are widely used to secure the lockable enclosures of food freezer appliances. The keyways of tubular locks, and the keys used to operate tubular locks, are commonly configured so the keys are snugly received in the keyways of the locks, and so the keys are retained once they have been inserted into the keyways. If children find operating keys that have been left in the keyways of food freezer locks, the children are sometimes tempted to use the keys to operate the food freezer locks, and to turn the lockable enclosures of food freezer appliances into playthings.
It is customary to take precautions to ensure that children do not easily gain access either to the keys that operate the locks of food freezer appliances, or to the keys of locks that control access to other types of lockable enclosures where children are likely to suffer harm they should become entrapped therein.
One precaution in wide use is to provide legibly printed warnings on the graspable bows of the keys to the locks of food freezers—warnings urging that the keys not be left in the keyways of the food freezer locks, and that the keys be kept at locations removed from the food freezer appliances. A typical warning in wide use is:                Caution: To Help Prevent Child Entrapment Keep Key Out of Reach of Children and Away from Food Freezer        
Proposals have been made from time to time for providing the locks of food freezer appliances and other lockable enclosures with a variety of mechanical contrivances for ejecting operating keys unless the keys are being used to operate the locks. Few if any of these proposals have achieved much acceptance due in large part to their complexity, their cost, and often due to their failure to achieve reliability during lengthy service lives.
The Problem of Food Freezer Keys being Left in Keyways
Some people who leave the keys to food freezer locks in the keyways of the locks do so inadvertently. This can easily happen inadvertently for two at least two reasons.
First, the vast majority of food freezer locks in use today are of the tubular type—and, the tubular keys are almost always sized and configured to provide a reasonably snug fit when inserted into the tubular keyways of the locks. The keys are not designed to fall from the keyways once inserted—but rather are intended to be retained in the keyways so inserted keys can be used quickly and easily. No designer of a food freezer lock has wanted the key that operates the lock to drop from the keyway, or to be difficult to use.
Second, the tubular keys and the tubular keyways of the locks are almost always provided with interfitting components, formations or parts that cooperatively engage. Most tubular keys have a radially outwardly extending formation—a small projection or lug—that must be inserted through a slot, cut or recess provided by the lock adjacent the keyway of the lock—and, these interfitting formations not only require that a tubular key be very specifically turned to a particular orientation in order to be inserted, but also provide a means of positively retaining the key in the keyway once the key has been fully inserted and turned even slightly so that the small projection or lug is caused to reside behind a curved, radially inwardly extending formation provided by the lock adjacent the tubular keyway of the lock. Sometimes it is simply more convenient for the key to be left in the keyway than it is to fuss with turning the key to the exact orientation required to effect withdrawal of the key from the keyway.
Some people deliberately leave the keys to food freezer locks in the keyways of the locks. They like the convenience of being able to use the already-in-place key like a doorknob—to open the food freezer easily whenever desired. They do not like having to chase about to find the key to a food freezer lock wherever the key may have been placed or secreted the last time the freezer was opened and locked.
A problem that commonly arises (if the tubular key to a food freezer lock is left in the tubular keyway of the lock) is that the key probably has already been used to operate the lock—which means that the key has already correctly rearwardly moved the tumbler pins of the lock the exact distances needed to unlock the lock—hence the tumbler pins are already correctly depressed to make it quite easy to unlock the freezer once the key has already been turned in the keyway of the lock—so, it quite often is the case that a key left in a food freezer lock simply needs to be turned slightly to the “unlocked” orientation in order for the lockable closure of the food freezer to be opened. No thoughtful manipulation of a left-in-place food freezer key likely is needed to open the sizable enclosure of a food freezer, other than to turn the key less than a quarter-turn to an “unlocked” orientation, and suddenly the closure of the food freezer may nicely “pop open.” This is often how the dreadful problem of child entrapment begins.
Few persons who leave the keys to food freezer locks in the keyways of the locks realize or appreciate that a left-in-place food freezer key is quite like a loaded and cocked gun that needs only minuscule movement of its trigger for a life-threatening problem to begin.
What the present invention seeks to prevent is not only the problems that arise because the keys to food freezer locks are either inadvertently or deliberately left in the keyways of food freezer locks, but also such problems as can arise if children or others find a correctly configured food freezer key that has not been left in the keyway of a food freezer lock. A feature of the present invention can make it at least somewhat difficult for even a correctly configured tubular key to be used to successfully operate a tubular food freezer lock unless the person in possession of the key understands how the key needs to be oriented during keyway insertion.